Telescope.



J. HARTNESS.

TELESCOPE.

APPLICATION PILED'NOV. 25. 1911.

1,045, 1 42, Patented Nov. 26, 1912.

12 SHEETSSHBET l.

J. HARTNESS.

TELESCOPB.

APPLICATION IILED nov. 25, 1911 1,045, 142. Patented Nov. 26, 1912.

12 SHBETS*SBEET 2.

-mummmmnu J. HARTNESS.

TELESGOPE.

APPLICATION IILED NOV. 25, 191L 1 ,045, 1 42. Patented Nov. 26, 1912.

12 SHEETS*SHEET 3 J. HARTNBSS.

TBLESCOPE.

APPLICATION PILED 11ov.25, 1911.

1 ,045, 142. Patented Nov. 26, 1912.

12 SHEETS-SHEET 4.

J. HARTNESS.

TELESGOPE.

APPLICATION IILED NOV. 25, 1911. 1,045,142. Patented Nov. 26, 1912.

12 SKEETS-SHEET 5,

' a zg. 4

J. HARTNBSS.

TBLESCOPE.

APPLICATION PILBD NOV. 25. 1911.

1,045, 142. Patented Nov. 26, 1912.

12 SHBETSSHBET 6.

J. HARTNBSS.

TELESGOPB.

APPLICATION IILED NOV. 25, 1911.

Patented N 0V. 26, 1912.

J. HARTNESS.

TELESCOPE.

APPLICATION IILED NOV.25, 1911.

Patented Nov. 26, 1912.

12 SHBETSSHEET B.

mwo h J. HARTNESS.

TELESGOPE.

A.PPLITIQN IILED NOV. 25, 1911. 1,045,142. Patented Nov. 26, 1912.

12 SHBETS-SHBET 9.

-yllllllll//llllA- J. HARTNBSS.

TELESCOPE.

APPLICATION IILBD nov. 25, 1911.

Patnted Nov. 26, 1912.

12 SHEETS-SHEBT 10.

J. HARTNESS.

TELESGOPE.

APPLICATION IILED NOV. 25. 1911.

1,045,142. Patented Nov. 26, 1912.

12 SHEETS*SHEET Il.

J. HARTNESS.

TELESCOPE.

APPLICATION IILED NOV. 25, 1911. 1,045,142, Patented Nov. 26, 1912. 12 SBEETSSHEET 12- 4i 42 JAMES HARTNESS, 0F SPRINGFIELD, VERMONT.

TELESCGPE.

Specification of Letters Patent.

Patented NOV. 26, 1912.

Application filed November 25, 1911. Serial No. 662,340.

''o aZl w7z0m it may conccrn:

Be it known that I, JAMES HARTNESS, a citiZen of the United States, and re sident of Springfield, in the county of \V1ndsor and State of Vcrmont, have invented certain new and useful Improvements in Telescopes, of which the following is a specificat1on,

This invention has relation to equator1al refracting telescopes.

The primary object of the invention is to provide a structure in which observations ma y be made without disoomtort to the observer, without limiting his range of observation, and without detriment to instrumental precision. Speaking generally, th1s is accomplished, according to my invention, by providing a closed structure of non-conducting material, having a dome or turret arranged to move about an axis parallel With the axis of the earth. The space w1thin the structure may be heated in the winter and cooled in the summer, irrespective of outside atmospheric temperatures, so that the observer may work at all times in an agreeably tennpered atmosphere. The telescope tube is located outside the dome and is pivotcd at its inner end to the turret or dome so as to swing about an axis perpendicular to the axis of the dome or to a line parallel to said axis. The eyepiece is substantially in alinement with the pivot, and is located within the dome or turret, the bundle of light rays being reflected from the object glass to the eyepiece by a single prism or reflector located at the elbow or junction of the axes of the evepiece and the telescope tube. As a result of this construction, the tube is swung about its pivot to obtain the desired angle of declination, and the turret or dome, With the tube supported thereby, is rotated about the axis to secure the dosired angle of right ascension.

Iu:mnuch as the tube is pivoted at one ond, il ira dcsirable not only to counterweight it, but also to provide a stay or brace for supporting and bracing the free end, and this is accomplislied by a weight0d arin pivoted to the turret or dome on the declination axis of the tube. but on the side of the turret opposite that to Wlll(ll the tube is pivoted, and connected to the free end of the tube at one or more points. Thus the pivot for the tube is relicved of a part of the '(i{Illt of the tube as well as of all lorsional strains. The counterweighted arm acts wholly as a support or countei'poise for porting structure.

the free end of the tube in one position of the turret, and, when the turret is in an- .other position, it acts wholly as a brace,

while at other times it acte partially as a brace and partially as a support for the tube, these functions depending upon the position of the inclined turret.

The turret or dome is preferably supported upon rolls, of which there are two sets. One set of rolls maintains the axis of the turret in parallelism with the earths axis, and the other set holds the center of the turret in a fixed position relatively to the supporting structure or building to facilitate convenience in measurement of the angular position of the telescope as to hour position or right ascension. Some of the rolls of the second set may be utilized for efl'ecting the rotation of the turret, for securing the desired angle of right ascension, or for following a celestial body. To this end, a motor and suitable powertrammitting connections are employed, and controlling or governing devises therefor are 10- cated within the dome or turret so that they may, if oesired, be manipulated by the observer while the latter has his eye at the eyepiece. In order that the hour position of the tube may be easily determined, I metcrably employ a ring or hour circle which is supported by the dome, and an index, on the base or supporting structure. In practice, I preferably mount the circle or ring so that it may be rotated relatively to the dome, and for convenience locate two diametrically opposite indexes on the dome.

Any convenient mechanism under control of the observer is provided for moving the telescope to the desired angle about its declination axis, and for this purpose the illustrated embodinzent of the invention is provided with worms operated by a hand wheel and engaging a worm wheel connected to the tube adjacent its elbow.

In addition to the features which have been briefl v referred to, the invention com prises other features of construction and arrangement which are illustrated upon the drawings, described in the follmving specification, and pointed out in the claims.

eferring to the drawings;Figure 1 represents a side elevation of the telrscopc and a longitudinal vertical section of the sup- Fig. 9 rcpresents a floor plan of the upper compartment which the observer occupies. Fig. 3 represonls a lloor resents a side elevation of the turret and telescope, and a portion of the housing. Fig. 7 represents an elevation of the rolls for turning the turret, and a train of gears for driving the rolls. Fig. 8 represents another elevation of the same rolls with the train of gears in cross section. Fig. 9 represents a sectional view of clutch mechanism for driving the train of gears represented in Figs. 7 and 8. Fig. 10 represents a side elevation, partly in section, of transmission gearing and clutch mechanism for driving the turret. Fig. 11 represents a horizontal section on the plane indicated by line 1111 of 10. Fig. 11 re resents a similar section showing a modi cation, (see sheet bearing Fig. 3). Fig. 12 represents a hori zontal section on the plane indicated by line 1212in Fig. 10. Fig. 13 represents a section in the plane indicated by line 1313 in Fig. 10. Fig. 14 represents a section in the plane indicated by line 14-14 in Fig. 10. Fig. 15 represents a vertical section in the plane indicated by line 1515 in Fig. 10. Fig. 16 represents a vertical section, on a larger scale, of a friction driving connection indicated in Fig. 10. Fig. 17 represents, on a relatively large scale, a portion of the turret and the meeting port1ons of the telescope tubes in which are mounted respectively the object glass and eyepiece. Fi 17 represents a perspective view of the rol stud. Fig. 18 represents an end view of the eyepiece and the mechanism for turning the telescope to the desired angle of declination. Fig. 19 represents an edge view, partly in section, of the operating mechanism included in Fig. 18. Fig. 20 represents a section on the plane indicated by line 2020 in Fig. 18. Fig. 21 represents a section in the plane indicated by line 21-21 in Fig. 20. Fig. 22 represents a development of a vernier for the operating mechanism included in Figs. 18 to 21. Fig. 23 represents an elevation of a portion of a gage ring for determining the position of the turret according to the desired right ascension. Fig. 24 represents an edge view of the same portion of the ring included in Fig. 23. Figs. 25 and 26 represent diametrically opposite portions of the gage ring and diametrically opposite index devices adapted to coperate with the ring. Fig. 27 represents 8. section on the plane indicated by the line struction.

2727 in Fig. 25. Fig. 28 represents an de vation, partly in section, of a modified form of turret and mounting therefor. Fig. 29 represents a side elevation of a turret and mounting with a telescope of modified con- Fig. 30 represents an elevation of the tube included in Fig. 29. Fig. 31 represents a section on the plane indicated by line 3131 in Fig. 29. Fig. 32 represents a section in the plane indicatedby line 3232 in Fig. 29. Fig. 33 represents an clevation of an eccentric stud foradjusting the objective tube included in Figs. 29 to 31. Fig. 34 represents a section on the plane indicated by line 3434 in Fig. 29. Fig. 35 represents 3, section in the plane indicated by line 35-35 in Fig. 34. Fig. 36 represents an end elevation of the eyepiece included in Fig. 34, and the operating mechanism for turning the objective tube to the desired angle of declination.

The same reference characters indicate the same parts wherever they occur.

Geneml st7uoture.Referring first to Fig. 1, the eyepiece of the telescope is indicated at 40, and the tube for holding the object glass is indicated at 41. The telescope as a whole is movably mounted in a revoluble head or dome 42 hereinaffer termed a turret. The turretis mounted to turn upon an annular base 43 and is disposed so that its axis extends at an angle to the horizon, which axis is determined by the geographical location of the telescope. In the present instance, the observatory as illustrated is intended for a latitude approximately 13 degrees 20 minutes north of the equator, and therefore the axis is disposed at an angle of 46 degrees 40 minutes from the zenith and points north. In other words, the axis of the turret is parallel with the axis of the earth, and consequently I refer to the turret as being movable about the polar axis or an axis coincident therewith.

For the purpose of comfortably housing the observer, the eyepiece 40 is effectuall y in closed Within the dome and the supporting structure wherein the temperature may be regulated as desired by the observer. The supporting structure housing, as illustrated by Fig. 1, and also by Figs. 2, 3, 6 and 29, is constructed of any preferred waterproof m11- terials, such, for example, as concrete. The walls 44 of the housing are preferably provided with suitable air spaces for the purpose of insulating; and, as sho m by Fig. 1, the air spaces are the result o i incorporating hollow tiles 44 into the concrete. In this adaptation of the housing, the inclosure for the observer comprises an upper compartment 45 and a lower compartment 46.

The floor of the upper con1partment is shown as being substantially at the level of the ground. which level is indicated at 47'. An observing platform, whereon the observer may stand or be seated when using the telescope, is indicated at 48.

Glazed windows 49 are provided in the roof of the housing, and glazed -apertures 42" are provided in the turret. The temperature of the inclosure may be regulated as desired, by suitable means indicated conventionally at 50. A heating medium such as steam or hot water, or a cooling medium, may be circulated through the radiator or coil50. A supply pipe 51 is provided for delivering fresh air to the observer standing upon the platform. A blower, indicated at 52, is connected with the supply pipe to force the supply of air through the supply pipe from any convenicnt source. The mechanism, hereinafter explained, for turning the turret 42 is driven by a suitable motor (in the present instance an electric motor) which may be governed by a rheostat 53 located within easy reach of the observer upon the platf0rm 48. Electric switches 54 are also located near the 'platform, whereby the observer may control the blower 52 and any other eleotrical devices, such for example as lamps which are indicated at 55.

The d0me or temet.The turret, in which the telescope is mounted and which may consist of a metallic casting, covered if desired With insulating material, rests upon rolls 42 (Figs. 3, 4 and 17) which are mounted in the annular base 43. The rolls are free to turn upon eccentric portions 42" of studs 42 (Figs. 17 and 17),and the studs are fixed with relation to the base by suitable means, such as set screws 42". By turning the roll studs, the rolls may be adjusted so that the turret Will bear equally upon them all, and the exact parallehsm of the turret and the earth axes may be restored if the settling of the building bas altered its position. The turret and base are provided with overlapping cylindric flanges 42 and 43", which flanges have only suflicient clearance to prevent contact and are adapted to prevent, to a great extent, the admission and escape of air.

The turret is formed with an annular flange 42 within the circle of the rolls 42. T he inner cylindric surface of the flange 42 bears upon driving rolls 56. (See Figs. 3", 4, 7 and 8.) In the present instance, there are four or these driving rolls and they are disposed at suitable intervals near the top of the base 43 so that the weight of the inclined turret Will secure the necessary traction. The rolls are formed upon or aflixed to shafts 56 and are supported by the base 43. As shown by Fig. 8, anti-friction bearings 56" are provided for the shafts and are arranged as closely as possible to the rolls so as to minimize the friction due to the weight of the turret. As shown by Figs. 3* and 4, the flange 42 is engaged at diametrically opposite points on the horizontal diameter by rolls 57 whose function is to prevent lateral movement of the turret and to hold the turret so that its axis will coincide with that of the base. The rolls 57 are mounted upon adjustable blocks 57 which in turn are mounted upon the base by pivot studs 57". Adjusting devices indicated conventionally at 57 are adapted to engage the blocks t0 position the rolls. The base is provided with a fourth set of rolls, which are indicated at 58 and are diametrically opposite those at 56. These rolls are arranged near the bottom of the base so as to engage the outer cylindric surface of the flange 42. The function of these rolls is to partially support the Weight of'the turret so as to relieve the driving rolls 56 to some extent, but not to so great an extent as to deprive the rolls 56 of the requisite pressure drivingthe turret. The employment of the rolls 58 is not necessary for the support and operation of the turret, but they are provided only for structural reasons. The diameter of the flange 42 and the internal diameter of the base are such as to afiord suflicient space for the observer to use the telescope in any position which it may occupy.

The telescope.As shown by Fig. 17, the telescope comprises in addition to the objectivetube 41, a tube 41 for the eyepiece 40, which is perpendicular to the axis of the dome or turret or to a plane including said axis. The tubes 41 and 41 are disposed at an angle of degrees With relation to each other, and the rays which are refracted and bundled by the object glass at the free end of the tube 41 are refiected to the eyepiece by a reflector which in the present instance is in the form of a prism, indicated at 59 and located at the elbow of the tube 41, in the declination axis thereof. The tube 41 is formed for the reception of a finder 60 to which the rays are reflected by another reflector which is likewise shown in the form of a prism and which is indicated at 60". The reflector 60 is mountedin a holder 60 which projects beyond the tube 41 and is provided with an opening 60 for the admission of rays.

The tubes 41 and 41 are fixd with relation to each Other. A sleeve 61 surrounds the sleeve 41" and is afl'ixed in bearings 61" in the turret. The tube 41 bears in and turns relatively to the sleeve 61, the tube being arranged so that its axis intersects and is disposed as stated at an angle of 90 degrees to the axis of the turret or to a line parallel thereto.

The turret is provided with a countcrweight which is disposed to counteract the weight of the telescope so that the turret will turn freely. The free end of the tube 41 is supported or braced by a trussed conncction indicated at 62 in Figs. 1, 5 and 0.

This connection extends to a cap or head 62 which is rotatably mounted in any suitable manner upon a tubular pivot 62*. This pivot extends into the turret in alinement with the tube 41 at a point diametrically opposite the latter and is suitably secured in bearings indicated in Fig. 3 at 62". An arm 62 afiixed to the head 62", and constituting at it were an extension of the arm or braee 62, is provided vvith a weight 62 which is adapted to balance the tube 41 so that it Will be free to swing about the axis of the tubes or pivots 41 and 62. This weight also tends to balance the turret so that the latter Will be free to turn about its axis. In the present instance, the tube 41 requires a counterweight slightly heavier than that required by the turret to counteract the weight of the tube, and for this reason the turret is provided with counterweights, such as that indicated at 62 so that it may balance in all positions.

Zl[ec7zanism for securing angle of declnatz'on.The mechanism for turning the teleseope relatively to the turret to the desired angle of declination is shovvn by Figs. 17 to 21. A worm wheel 63 is keyed or otherwise afiixed to the tube 41". This Worm wheel is engaged by two worms 64 which are mounted upon the turret at diametrically opposite points with relation to the center of the wheel and which are operated in unison. Referring to Figs. 20 and 21, each worm is formed upon a sleeve 64 to which is keyed the hub of a spiral gear 64". The two spiral gears 64 intermesh with spiral gears 65, both of which are afiixed upon a transverse shaft 65. A third spiral gear 65", disposed midway between the ends of the shaft, meshes with a driving gear 66 which is aflixcd to the shaft 66. The shaft is provided with a hand wheel 66 which is so located that the observer may operate it while looking into the eyepiece.

The rim of the worm wheel 63 is provided with a gage or scale consisting of marks 63 which divide the circle of thewheel into 360 dcgrees. Fig. 19 shows two index fingers represcnted by dotted lines and indicated at 63". These fingers are arranged diametrically opposite each other and overhang the worms 64. Their location is indicated in Fig. 18, and they are adapted to coperate with the scale 63 upon the wheel. A vernier is provided for cnabling the observer to adjust the telescopc more accurately than would be possible by means of the marks 63 alone. The vernier, as represented by F 1g. 29, is adapted to enable the observer to adjust ll1e telcscope witbin one second of the dcsircd angle. As shown by Fig. 20, the sleme 64 is formed with a flange 64 which oxtcnds outside the hub of the gear 64". Ibis flangc is provided with the seule 64, (sec Fig. 18). The end of the flangc (34 abuts against an adjustable collar 64 upon which the coperative scale 64 of the vernier is provided. The collar 64 is held (sec Fig. 21) by set screws 64 in fixed relation to a bracket 64, in which the worm is mounted by means of a rod or spindle 64. The gearing for turning the worm wheel 63 is such that one revolution 'of the worms 64 is equal to one degree of angular or rotative movement of the wheel 63. The vernier enables the observer to adjust the Worm sleeve with great precision; and the movement of the sleeve, being greatly reduced in transmission to the wheel 63, gives au adjustment as nearly accurate as could bc de sired. The function of the adjusting screws (54 is to obtain accuracy in positioning one of the elements of the vernier, and, after the desired position has once bcen found, it is not necessary thereafter to change it.

A modified form of mechanism for moving the objective tube to the desired angle of declination is illustrated by Figs. 34, 35 and 36, hereinafter described.

T mwet mom'ng meckam'sm for m'gfit ascension.-A motoris provided for turning the turret to the desired position to obtain the angle of ascension and for driving the turret slowly to -neutralze the earths diurnal motion. The gearing for driving the rolls 56is shown best by F igs. 3*, 7 and 8. Referring first t0 Figs. 7 and 8, a gear 56 is keyed or .otherwise aflixed to each of the roll shafts 56". Two of these gears mesh with a pinion 56 which is loosely mounted upon one of the intermediate shafts 56. The other two gears 56 mesh with another pinion 56 which is likewise loosely mounted upon the other intermediate shaft 56". Each of the two pinions 56 is aflixed to or compounded with a gear 56; and the gears 56 mesh with small gears 56 which, in the present instance, are formed upon the same hub or sleeve as indicated at 56 in Figs. 3*, 8, 9 and 10. The sleeve is mounted upon and aflixcd to a power shaft 67, the axis of which is parallel to the axis of the turret. By this arrangement, the roll shafts are rotated synchronously in the same direction.

The shaft 67 may be driven at either of two speeds by the same motor. The bevel gear 68 is aflixed to the shaft 67 for driving the shaft at a relatively fast speed to enable the observer to quickly find the approximace angle of ascension of a star or planet. Friction cluteh members 69 and 69 are mounted upon the shaft 67 and are adapted to be driven at a relatively slow speed to impart rotation to the turret to counteract the diurnal motion of the earth.

The gear 68 (sec Figs. 3 and 10) n1esheS with a bevel gear 68 which is afiixed at the upper end of a vertical shaft 70 hereinaitcr termed the fast-spced shaft. This sl1al't is pref'erably made in two sections, the lower section of which is indicated at A suitable friction coupling device 70 (which it is not necessary to describe in detail) is provided for connecting the abutting ends of the two shaft sections (sec Fig. 16), the function of which is to avoid damage in case the movement of the turret is obstructed. Gearing is provided for driving the shaft section 70 in either direction. As shown by Figs. 10 and 12, a worm gear 70 is mounted upon the section 70 near its lower end. This worm gear is loose upon the shaft and is provided with clutch teeth 70". A clutch 70 (Fig. 14) is splined upon the shaft and is provided with clutch teeth 70 adapted to be moved to and from driving engagement with the teeth on the gear 70. The gear 70 is driven by a worm 71 aflixed t0 a shaft 79. This shaft may be regarded as the prime power shaft, and it may be driven by any suitable means. It is preferred, bowever, to locate the source of power outside the observatory housing, for the purpose of avoiding as far as possible all noise incident to the working of a motor.

As shown by Fig. 2, a motor 73 is installed in a separate housing 74 apart from the housing of the observatory. The housing 74 may be wholly or partially disposed below the ground level. The driving connection between the motor and the power shaft 72 is, in the present instance, a belt 75 which passes over a driving pulley 7 3* on the motr shaft and over a pulley 72 on the shaft 79. A sleeve or casing 72 is provided for inclosing the shaft 72 and inclosing. the clectric conductors 73" which lead to the motor. The shaft 72 is preferably made in two sections, and the sections are coupled by a coupling device 7 2 adapted to compensate for any angular relation of the two sections. The several worms and gears and toothed clutch members hereinbefore described are inclosed ina gear case 7 2 standing on the fioor of the observatory.

In order to provide for turning the turret in a reverse direction, a Second worm gear 76 is arranged to engage the worm 71. The latter gear is loosely mounted upon a counter-shaft 76 and is provided with clutch teeth 76. A second clutch sleeve 76 is splined upon the shaft 76 and is provided with clutch teeth 76 adapted to be moved to and from engagement with the teeth on the gear 76. An oscillatory shipper 77 connected with the two clutch sleeves is affixed upon a rock shaft 77 and is adapted to couple either of the clutch sleeves with its respective worm gear. The two worm gears are. of course, rotated in opposite directions. lxcferring to Figs. 10 and 13, pinions 70 and 78 are affixed respectively to the shaft section 70 and to the conntershaft 76. An intern1ediate gear 76 is adapted to transmit rotation from the pinion 76 to the pinion 70. N W, therefore, when one of the clutch sleeves is placed in operative engagement with one of the worm gears, the shaft 70 will be driven in one direction; whereas, if the other clutch sleeve is placed in engagement with the other worm gear, the shaft Will be driven in the opposite direction. This motion will be transmitted through the friction coupling 70 and the train of gears to Fig. 10, a hand lever 78 is pivotally corinected at 78 t0 a collar 78 which is loosely mounted upon the upright shaft 77 and isdisposed between collars 78 and 78", both of which are affixed to the shaft. The collar 78 is provided with radial teeth 78 which are adapted to be engaged by a tooth or projection 78 on the lever 78. As shown by Fig. 10, this lever occupies an inoperative position wherein it is in a position out of the way of*the observer. Both clutch sleeves are disengaged from the worm gears with which they are adapted to coperate. When it is desired to use the fast-speed shaft to turn the turret in one direction or the other, the desired clutch may be connected. by swinging the lever 78 about its pivot so as to move the tooth 78 between two teeth 78 of the collar 78", this, bringing the lever 78 in a radial position with relation to the shaft 77 and operatively connecting the lever with the shaft so that the shaft can be turned slightly in either direction by swinging the lever laterally. A slight turning of the shaft is suflicient to efiect the desired movement of the shipper 77. When the fast-speed shaft is no longer needed for driving the turret, both clutch sleeves may be left disconnected as shown, and the lever 78 may be swung out of the way to the position which it occupies in Fi 10.

The main drivi1ig shaft %2 is provided with a second worm, indicated at 79 in Figs. 10 and 12. This worm, when driven at the right speed, efi"ects a movement of the turret which counteracts the diurnal motion of the earth. The speed of the motor can, of course, be regulated by the rheostat 53. Rotation is transmitted from the worm to a worm gear 79" which is aflixed to the vertical shaft 79". The upper end of this shaft is connected by gearing to the lower end of a shaft 79.- As shown by Fig. 10, the lower end of the shaft 79 is formed with :1 socket 01' bearing 79 to receive the upper end of the shaft 79 whereb v the two shafts are kept in alinement. The upper end of the shaft 79 is provided with a worm 80 which engages a gear 80" formed upon or alfixed to the clutch member 69 hereinbefore' mentioned. A pinion 7 9 afiixed to the shaft 79 engages pinions 7 9 which in turn engage another internal ear tooth 79 formed upon a member 79 a xed to the shaft 79. The

inions 79 are mounted upon a disk 79 through which the shaft 7 9 extends loosely. When the disk 79 is held stationary, the shaft 79 is driven at a much slower speed than the shaft 79; and this motion, When the clutch members 69 and 69" are connected, is transmitted to the turret.

The disk 7 9 is a device for correcting the position of the turret whenever the speed of the driving mechanism as imparted by the shaft 79 does not accurately connteract the earths diurnal motion. As shownby Fig. 11, the rim of the disk 79 is provided with teeth 81, and these teeth are adapted to be engaged by a pin or projection 81 projecting from a rock shaft 81. The rock shaft is provided with a hand wheel 81 whereby the pin may be moved to or from engagement with the teeth 81. The pin is engaged between two of the teeth, as shown by Fig. 11, in order to arrest the rotation of the disk 79, so that the pinion 79 may drive the internal gear 7 9. So lon as the diurnal movement of the telescope fo lows the planet under observation, the disk remains locked; but, if the movement of the telescope should be too fast or too slow, the position of the telescope may be corrected, first by turning the hand wheel 81 t0 unlock the disk and thereafter arresting the movement or increasing the movement of the shaft 79. This, of course, may be done without stopping the. motor. When the disk 79 is 11nlocked, it will revolve with the shaft 79 so that the pinions 79 will describe a planetary movement within the gear 7 9 without driving the latter. A hand wheel 81 is loosely mounted upon the shaft 79 and is supported by a collar 81 affixed to the shaft. The hand wheel is coupled in any suitable way with the hub of the disk 79 so that the disk may be turned by means of the hand wheel. As shown by Figs. 10 and 11, the hub of the hand wheel is provided with a pin 81 which projects into a recess in the hub of the disk. If the movement of the shaft 79 as effected by the motor is too slow, it may be increased bv tnrning the hand wheel 81 after first disengaging the pin 81 from the teeth 81. On the other hand, if the movement of the shaft 7 9 is too fast, the position of the telescope may be correoted by merely disengaging the pin 81 from the teeth 81 for a sufiicient length of time to enable the earth to overtake the already advanced position of the telescope.

The correcting device is within easy reach of the observer, 80 that it may be manipulated while a planet is under observation, and the observer may be enabled to time the operation of the correcting device without looking away from the telescope. The han-' dle 78 and the hand wheel 81 are likewise accessible without necessitatin the movement of the observer away fromt e eye-piece.

A modified form of correcting device is shown by Fig. 11, (sec sheet bearing Fig. 3*). This device comprises a worm 81 on the shaft 81 in place of the pin 81. The worm not only serves to hold the disk 79 against rotation, but itis adapted to impart rotation in either direction, thus dispensing with the necessity of the hand wheel 81". In other words, the worm is adapted to perform the function of the pin 81 as well as the function of the hand wheel 81.

The clutch members 69 and 69 are pro vided with operating mechanism whereby it is impossible to couple thexn when the shaft is being used for turning the turret. As shown by Fig. 9, the clutch member 69 is loosely mounted upon the shaft 67, and the clutch member .69 is slidingly connected with the shaft by a pin 69. This pin extends through an elongated tranverse opening 69 formed in the shaft. This form of connection enables the clutch member 69 to move longitudinally with relation to the shaft, but holds one against rotation relatively to the other. The shaft is bored for the reception of a clutch-operating rod 69", and the pin 69 extends transversely throngh this rod so as to be shifted by it. A spring 69 arranged within the shaft is compressed so as to act against the inner end of the rod with the efi'ect of normally holding the clutch member 69 in clutched engagement with the member 69. A hand lever 82 accessible to the observer is adapted to engage the buter end of the rod, with the effect et disconnecting the clutch members. This lever is pivoted at 82, and, as shown by Fig. 15, is provided with a laterally extending pin or projection 89 the end of which is beveled. This projection is adapted to cooperate with a similar pin or pro ection 89 on an arm 82 aflixed to a part of the stationary frame work. The pins 82" and 89 Occupy the relation shown by Fig. 15 When the clutch member 69 and 69 are coupled as shown by Fig. 9. The lever 82 is formed with a projection 89 which is adapted to enter an opening formed in an arm 82 affixed at the upper end of the shaft 77 As shown by Fig. 10, the shaft 70 is disconnected from the source of power, becausv both of the clutch sleeves 70 and 70 are disconnected from the worm gears which have correspondin clutch teeth. Vhatevcr movement the sha t 70 receives under thc e conditions it receives through the goar 438 and clutch members 69 and 69. When the projection 82 occupies the opening in the arm 82 the shaft 77" is.locked so that it is impossible to move either of the clutch sleeves and 76 into driving position. At this time the friction clutch members 69 and 69 are connectcd, because they are released by the lever 82. VVhen it is desired to drive the turret by means of the shaft 70, it is first necessary to unlock the shaft 77. This can be done only bv withdrawing the projection 82 from the arm 82 and at the same time uncoupling the clutch members 69 and 69". \Vhen the hand lever 82 is moved to unlock the shaft 77, the projection 82 having the beveled end is moved downwardly past the projection 82, the beveled faces of the projections causing lateral flexure of the lever 82 until the projection 82 passes wholly below the projection 82". The lever may thon spring back to its normal lateral position wherein the projection 82* will engage the under surface of the projection 82 and look the lever in such position as to hold the clutch members 69 and 69 apart. The turret thereupon becomes wholly disconnccted from the source of power, and may be driven through the fast-speed shaft 70 by manipulating the clutch lever 78 hereinbefore described. Vhenever either 'of the toothed clutch sleeves 70" and 76 is in driving engagement with the corresponding worm gear, the position of the arm 82 prevents the release of the hand lever 82 and consequently prevents driving connection through the friction clutch members 69 and 69. In order to again drive the turrct through the medium of the friction clutch members. it is first necessary to d sconriect both of the toothed clutch members in ordcr to place the arm 82 in position to receive the projection 82 on the lever 82. The lever 82 may then be released from the projection 82 by a slight lateral flexure of the lever. whereupon it may be restored to the position shown and the friction clutch members may be coupled by the spring 69.

Hour circle.An annular gage or ring, hereinafter termed the hou circle, is'mounted upon the turret and is adapted to be used with reference to sidereal time to enable the observer to set the turret at a position corresponding to the desired right ascension. This hour circle is mounted upon the turret. as shown bcst b v Figs. 3* and 4". and is indicated at 83. It is formed with a 'fiange 83 and is supported by a pluraliy of studs 88 which project inwardly from a flange formed on the turret (sec Fig. 27). The inner face of the ring is provided with a scale having marks 83 (Fig. 24) which divide the circle into 24 divisions each representing one hour of time, and subdivide the hours into minutes. The ring is free to be rotated manually with relation to the turret and is used in conjunction with a stationary index mounted upon the base and with two indexes mounted on and movable with the turret. The stationary index consists of a block84 mounted in a'bracket 84 by trunnions 84". The bracket is aflixed to the base 43 in such manner that the block 84 Will bear against the under fiat face of the ring, and it is disposed at the zenith, 2'. e. in the vertical plane of the axis of the turret at the highest point of the ring. A mark 84, hereinafter terxned the zenith point, is provided on the block 84 and is adapted to be read in conjunction with the scale on the hour circle. The trunnions 84" are screw-threaded in the bracket 84 and are adapted to position the block 84 laterally so as to determine accurately the location for the zenith point.

The movable index members on the turret are shown in detail in Figs. 25. 26 and 27, and thcir positions are shown by Figs. 3 and 4". Each movable index comprises an adjustable member 85 and a bracket 85. The brackets are aflixed to the turret at diametrically opposite points, and the members 85 are connected to the brackets by trunnions 85. Each member 85 is provided with an index mark 85 which is adapted to be read in conjunction with the scale on the hour circle. The trunnions 85 are adapted to adjust the members 85 laterally so as to locate the marks 85 at precisely 180 degrees from each other and ninety degrees from the axis (if the eyepiece. In tmding a celestial body, the hour circle is moved to bring the figure on the scale, indicating the hour, minute and second at which said body is at zenith, opposite one of the indexes on the turret, and then the ti1rret is rotated to bring the figure on the hour circle, indicating the then sidereal time, to the zenith point on the base. Such minute adjustment as may be necessary may be made by the hand wbeel 81 in the manner hereinbefore explained.

As heretofore stated, the telescope is mounted in such manner as to eilectually protect the observer from out-of-door conditions. It is obvious, however, that the telescope may be mounted and operated in the manner explained without requiring a closed compartment for the observer. For example, Fig. 28 illustrates a construction Wherein the observer is not inclosed. This construction inoludes means for adjusting the base for the turret so as to locate the axis of the turret in exact parallelism with the polar axis of the earth. The base 43, in this instance, is provided with adjusting screws 43 which engage the foundation for the turret. By means of these screws, it is possible to adjust the base, and consequently the turret, with relation to the foundation so as to cause the axis of the turret to extend in the desired direction according to the latitude of the observatory. The turret, as shown by this figure, is of simpler construction than that hereinbefore considered, and it is operated by mechanism of comparatively simple construction. An internal cylindric surface of the turret bears against a single driving roll, indicated at 56. This roll is afiixed t0 a shaft 56 which is mounted in suitable bearings afforded by the base. A gear 80 is aflixed to the shaft and is driven by a -worm 80 mounted upon a vertical shaft 7 9".

Any desired mechanism may be provided for driving the shaft 7 9" at the desired speed and in the desired direction.

Figs. 29 to 35 illustfate a modified form of telescope which embodies some of the features of the telescope hereinbefore described, and it is mounted in a turret in the manner explained. In this modified form the 'objective tube is indicated at 41. The inner end of the tube is afiixed t0 a rotatable carrier 41". The eyepiece, indicated at 40, is fixed with relation to the turret, and the objective tube is therefore movable with relation to the eyepiece. The eyepiece is mounted upon a tube 41 which is afiixed in the turret. The outer end of the tube afi0rds a bearing for an annular flange 41 on the holder 41". A flange 41 formed on the tube, is engaged by an annular flanged member 41 which has screw-threaded connection with the holder 41". A reflector 59, here shown in the form of a pris1n, is adapted to reflect the rays from the tube 41 through tube 41 to the eyepiece. The holder 41 is provided with teeth 86 arranged to form an internal gear. This gear is engaged by pinions 86 which are afiixed to shafts 86. The shafts are parallel and are diametrically opposite with reference to the axis of the tube 41. The bearings for the outer ends of the shafts are afi'orded by the fiange 41, while the bearings for the inner ends are afiorded by abracket 87. The bracket is aflixed to the turret and aflords bearings for a transverse shaft 86. This shaft is provided with worms 86 which coperate with worm gears 86 afiixed respectively to the shafts 86". A spiral gear 86 afiixed to the transverse shaft coperates with a spiral gear 88 affixed upon a shaft 88. The shaft carries a hand wheel 88 whereby the various gears and shafts may beoperated in unison to turn the holder 41". The objective tube 41 is circular at its outer end and elliptical in its cross section at its inner end. One of the transverse partitionsior breaking up the refleeted rays within the tube is indicated in Fig. 32 at 89.

The trnssed connection 62 for supporting the outer end of the tube is connected by studs such as that shown in Fig. 33, whereby the position of the tube may be corrected to eliminate any defect due to sagging. The

connection 62 is provided with a yoke 62 the ends of which are connected to the tube by studs 62". The studs are formed with eccentric portions 62 which bear in blocks 62 afiixed to the tube. The outer ends of the studs 62 are provided with angular heads 62 whereby a wrench may be employed to turn the studs to the desired position. The shanks of the studs are screwthreaded, as indicated at 62, to receive clamping nuts 62 whereb they may be securely held after being ad]uStd.

It Will be apparent to astronomers from the foregoing description that I have provided an equatorial telescope (that isone having a mounting consisting of two pivotal joints, one called the polar axis, parallel to the earths axis, and the other called the declination axis and being at right angles to the polar axis or to a l1ne parallel therewith) which is unlimited in 1ts range and which is efiicient, not only optically, but also in point of mechanical precision, 'and furthennore in which there is no necessity of requiring a temperature in the dome equal to that of the external atmosphere. The range of observation is not limited by the base structure or housing since the tube may be directed to any point in the visible heaven. The methods of mounting the dome in circular and cylindrical tracks, and pivoting and counterpoisin the tube, enable them to be mainta1ned r1gidly and without vibration; and the power-transmitting mechanisms, within convenient control of the operator, permit the dome and tube to be positioned with ease and precision. In this connection I may point out that the turret or dome constitutes a circular ring bearing or polar pivot for the telescope, as distinguished from an arbor aboutwhich thetelescope may be swung. VVhile an arbor of small diameter mounted in separated bearings furnishes a reliable center control about which to move a body for accurate angular position, yet in a large tclescope, the necessary delicacy of poise is not favorable for stabilit of control. In the present case, however, t 1e turret has a circular plane surface which may be engaged at points remote from each other to hold the polar axis of the turret in perfeo parallelism with the earths axis, and a cylindrical surface with which may be enga ed the rolls or guides which prevent latera movexpent of the turret and insure a fixity of the polar axis, thus making itpossible to control the motion and angnlar position of the turret and tube around the polar axis with the necessary accuracy.

v In lieu of supporting the circular and cylindrical edge or rim of the turret by the two sets of rolls, it might be fitted in a hol- 1ow ring bearing, with or without interposed 

